A patch for issue 2085 has been posted. It now looks to see if the
StringNumber stencil is #f, and if it is, it avoids creating a StringNumber
grob.

I guess there are still likely to be issues to work out concerning the
differences between string-number articulations (inside of chord
constructs) and string-number events (outside of chord constructs).
Presumably the new code will be consistent, i.e. the difference between the
articulations and the events will go away?